title: Predicting the segregation profile of the Pt25Rh75(100) surface from first-principles.
abstract: The segregation profile of the Pt(25)Rh(75)(100) surface is studied by the combination of density functional theory calculations with the cluster-expansion method and Monte Carlo simulations. We construct the stability diagram for the surface layers, which allows the prediction of the most stable atomic configuration for a given average concentration in those layers. On this basis, we apply the cluster-expansion Hamiltonian in grand-canonical Monte Carlo simulations for the prediction of the temperature-dependent concentration profile. The experimentally found enrichment of Pt in the top layer and depletion in the second layer is nicely confirmed by the calculations.
authors.affiliation: Lehrstuhl für Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstrasse 7, 91058 Erlangen, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Welker
authors.forename: O
authors.initials: O
authors.lastname: Wieckhorst
authors.forename: T C
authors.initials: TC
authors.lastname: Kerscher
authors.forename: S
authors.initials: S
authors.lastname: Müller